1. Field of the Invention
The present invention relates to an apparatus for displaying a time distance until necessary images are formed.
2. Related Background Art
Image forming apparatuses such as copiers and printers are under development in which a time distance from the start to end of image forming operation is displayed on a display device which also displays a set image forming mode (paper size, the number of copies to be formed, magnification factor and the like). A function of predicting a time distance from the start to end of image forming operation in accordance with a set image forming mode and displaying the predicted time distance on the display device to inform a user of it, is now taken into consideration. For example, a message such as "take 3 minutes to end", "wait time is 3 minutes" and "predicted end time 11:20" is displayed. Another consideration is to display the state of image forming operation. For example, messages such as "take 2 minutes to end" and "take 1 minute to end" are sequentially displayed after a message "take 3 minutes to end" is first displayed.
In order to realize such a display function, it is considered to prestore time distances in various image forming modes and in accordance with this stored data, predict and display a total time distance required for the designated image forming mode.
Instead of prestoring various data in a memory, the total time distance may be predicted through calculation after measuring a scan interval for reading originals after the image forming operation is actually started.
Even if various data is prestored in a memory, the necessary time distance cannot be calculated if the memory does not store the data corresponding to an image forming mode designated by a user. With the method of performing a predictive calculation from the measurement of a scan interval for reading originals after the image forming operation is actually started, however, the total time distance cannot be calculated until the measurement is finished.
In order to calculate the time distances for all image forming modes, time data for all attribute data (parameter data of settable image forming modes) is required to be prestored so that the memory capacity becomes large. If time data for some of attribute data is prestored, the use frequency of prestored time data may become low because frequently used image forming modes are different from one user to another user. The frequency of predictive calculations becomes therefore low.
Even if a plurality of attribute data sets are stored in a memory, only one set is used so that the memory capacity is used wastefully. If the memory stores a number of same attribute data sets, the number of types of attribute data sets becomes small so that the capability of predictive calculations may become low. In this case, the measurement (e.g., measurement of scan interval) is required after the actual image forming operation starts so that the calculation time is prolonged.